Unless otherwise indicated herein, the materials described in this section are not prior art to the claims and are not admitted to be prior art by inclusion in this section.
A typical cellular wireless network may include a number of base stations that radiate to define wireless coverage areas, such as sectors and cells, in which mobile stations such as cell phones, tablet computers, tracking devices, embedded wireless modules, and other wirelessly-equipped communication devices can operate. In turn, each base station may be communicatively coupled to network infrastructure that provides connectivity to one or more transport networks such as the public switched telephone network (PSTN) and/or the Internet. With this arrangement, a mobile station within coverage of a wireless network may engage in air-interface communication with a base station and may thereby communicate via the base station with various remote network entities or with other mobile stations served by the base station.
In general, a cellular wireless network may operate in accordance with a particular air-interface protocol or “radio access technology,” with communications from the base stations to mobile stations defining a downlink or forward link and communications from the mobile stations to the base stations defining an uplink or reverse link. Examples of existing air-interface protocols include Code Division Multiple Access (CDMA) protocols such as IS-95, 1xRTT, and Enhanced Voice-Data Only (EV-DO); Global System for Mobile Communications (GSM) protocols such as General Packet Radio Services (GPRS) and Enhanced Data rates for GSM Evolution (EDGE); Advanced Mobile Phone System (AMPS); Universal Mobile Telecommunications System (UMTS); Long-Term Evolution (LTE); Wi-Fi; and Bluetooth. Each protocol may define its own procedures for registration of mobile stations, initiation of communications, handoff between coverage areas, and functions related to air-interface communication.
In accordance with the air-interface protocol, each coverage area may operate on one or more carrier frequencies and may define a number of air-interface channels for carrying information between the base station and mobile stations. Each carrier represents a physical transmission interface, i.e., a frequency used to transmit data, while a logical channel is used to transmit data, organize transmitted data, and identify each data type (such as traffic, control, and broadcast data). Forward-link and reverse-link communication may occur on respectively different carriers.
Each coverage area may define a forward-link control channel (or “forward paging channel”) used to transmit messages such as call setup procedures and registration instructions. Each carrier in a coverage area may include several forward paging channels, and each mobile station may be associated with at least one forward paging channel. The mobile-station forward-paging-channel assignments in a base station coverage area may be distributed over the available forward paging channels.
Mobile stations may be configured to periodically monitor their associated forward paging channel during an assigned time slot. The frequency at which a mobile station monitors its associated forward paging channel could vary, perhaps from once every few hundred milliseconds to once every several minutes.